package com.lxdp.service.impl;

import cn.hutool.core.bean.BeanUtil;
import com.lxdp.dto.Result;
import com.lxdp.dto.UserDTO;
import com.lxdp.entity.VoucherOrder;
import com.lxdp.mapper.VoucherOrderMapper;
import com.lxdp.service.ISeckillVoucherService;
import com.lxdp.service.IVoucherOrderService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.lxdp.utils.RedisIdWorker;
import com.lxdp.utils.UserHolder;
import lombok.extern.slf4j.Slf4j;
import org.redisson.api.RLock;
import org.redisson.api.RedissonClient;
import org.springframework.aop.framework.AopContext;
import org.springframework.core.io.ClassPathResource;
import org.springframework.data.redis.connection.stream.*;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.script.DefaultRedisScript;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import javax.annotation.PostConstruct;
import javax.annotation.Resource;
import java.time.Duration;
import java.util.Collections;
import java.util.List;
import java.util.Map;
import java.util.concurrent.ArrayBlockingQueue;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author hong
 * @since 2023-04-22
 */
@Slf4j
@Service
public class VoucherOrderServiceImpl extends ServiceImpl<VoucherOrderMapper, VoucherOrder> implements IVoucherOrderService {
    @Resource
    private ISeckillVoucherService seckillVoucherService;

    @Resource
    private RedisIdWorker redisIdWorker;

    @Resource
    private StringRedisTemplate stringRedisTemplate;

    @Resource
    private RedissonClient redissonClient;
    private static final DefaultRedisScript<Long> SECKILL_SCRIPT;
    static {
        SECKILL_SCRIPT = new DefaultRedisScript<>();
        SECKILL_SCRIPT.setLocation(new ClassPathResource("seckill.lua"));
        SECKILL_SCRIPT.setResultType(Long.class);
    }
    private BlockingQueue<VoucherOrder> orderTask = new ArrayBlockingQueue<>(1024 * 1024);
    private static final ExecutorService SECKILL_ORDER_EXECUTOR = Executors.newSingleThreadExecutor();
    @PostConstruct
    private void init(){
        SECKILL_ORDER_EXECUTOR.submit(new VoucherOrderHandler());
    }
    public class VoucherOrderHandler implements Runnable{
        String queueName = "stream.orders";
        @Override
        public void run() {
            while (true) {
                try {
                    List<MapRecord<String, Object, Object>> list = stringRedisTemplate.opsForStream().read(
                            Consumer.from("g1", "c1"),
                            StreamReadOptions.empty().count(1).block(Duration.ofSeconds(2)),
                            StreamOffset.create(queueName, ReadOffset.lastConsumed())
                    );
                    if(list == null || list.isEmpty()){
                        continue;
                    }
                    MapRecord<String, Object, Object> record = list.get(0);
                    Map<Object, Object> value = record.getValue();
                    VoucherOrder voucherOrder = BeanUtil.fillBeanWithMap(value, new VoucherOrder(), true);

                    handleVoucherOrder(voucherOrder);
                    stringRedisTemplate.opsForStream().acknowledge(queueName,"g1",record.getId());
                } catch (Exception e) {
                    log.error("处理订单异常",e);
                    handlePendingList();
                }

            }
        }

        private void handlePendingList() {
            while (true) {
                try {
                    List<MapRecord<String, Object, Object>> list = stringRedisTemplate.opsForStream().read(
                            Consumer.from("g1", "c1"),
                            StreamReadOptions.empty().count(1),
                            StreamOffset.create(queueName, ReadOffset.from("0"))
                    );
                    if(list == null || list.isEmpty()){
                        break;
                    }
                    MapRecord<String, Object, Object> record = list.get(0);
                    Map<Object, Object> value = record.getValue();
                    VoucherOrder voucherOrder = BeanUtil.fillBeanWithMap(value, new VoucherOrder(), true);

                    handleVoucherOrder(voucherOrder);
                    stringRedisTemplate.opsForStream().acknowledge(queueName,"g1",record.getId());
                } catch (Exception e) {
                    log.error("处理pending-list订单异常",e);
                    try {
                        Thread.sleep(200);
                    } catch (InterruptedException ex) {
                        throw new RuntimeException(ex);
                    }
                }

            }

        }
//        @Override
//        public void run() {
//            while (true) {
//                try {
//                    VoucherOrder voucherOrder = orderTask.take();
//                    handleVoucherOrder(voucherOrder);
//                } catch (Exception e) {
//                    log.error("处理订单异常",e);
//                }
//
//            }
//        }
    }
    IVoucherOrderService proxy ;

    private void handleVoucherOrder(VoucherOrder voucherOrder) {
        RLock lock = redissonClient.getLock("lock:order:" + voucherOrder.getUserId());
        boolean tryLock = lock.tryLock();
        if (!tryLock) {
            log.error("不允许重复下单");
            return ;
        }
        try {
            proxy.createOrder(voucherOrder);
        } finally {
            lock.unlock();
        }
    }


    @Override
    public Result seckillVoucher(Long voucherId) {
        UserDTO user = UserHolder.getUser();
        long orderId = redisIdWorker.nextId("order");
        Long result = stringRedisTemplate.execute(
                SECKILL_SCRIPT,
                Collections.emptyList(),
                voucherId.toString() ,
                user.getId().toString(),
                String.valueOf(orderId));
        int value = result.intValue();

        if(value != 0){
            return Result.fail(value == 1 ? "库存不足" : "不能重复下单");
        }

        proxy = (IVoucherOrderService) AopContext.currentProxy();
        return Result.ok(0);
    }

    //阻塞队列
//    @Override
//    public Result seckillVoucher(Long voucherId) {
//        UserDTO user = UserHolder.getUser();
//        Long result = stringRedisTemplate.execute(SECKILL_SCRIPT, Collections.emptyList(),voucherId.toString() ,user.getId().toString());
//        int value = result.intValue();
//
//        if(value != 0){
//            return Result.fail(value == 1 ? "库存不足" : "不能重复下单");
//        }
//        VoucherOrder voucherOrder = new VoucherOrder();
//        long orderId = redisIdWorker.nextId("order");
//        voucherOrder.setId(orderId);
//        voucherOrder.setUserId(user.getId());
//        voucherOrder.setVoucherId(voucherId);
//        save(voucherOrder);
//        proxy = (IVoucherOrderService) AopContext.currentProxy();
//        orderTask.add(voucherOrder);
//        return Result.ok(0);
//    }

//    @Override
//    public Result seckillVoucher(Long voucherId) {
//        SeckillVoucher voucher = seckillVoucherService.getById(voucherId);
//        if (voucher.getBeginTime().isAfter(LocalDateTime.now())) {
//            Result.fail("秒杀未开始");
//        }
//        if (voucher.getBeginTime().isBefore(LocalDateTime.now())) {
//            Result.fail("秒杀已结束");
//        }
//        if(voucher.getStock() < 1){
//            Result.fail("裤存不足");
//        }
//        Long userId = UserHolder.getUser().getId();
////        SimpleRedisLock lock = new SimpleRedisLock("order:" + userId, stringRedisTemplate);
//        RLock lock = redissonClient.getLock("lock:order:" + userId);
//        boolean tryLock = lock.tryLock();
//        if (!tryLock) {
//            return Result.fail("一人限购一单");
//        }
//        try {
//            IVoucherOrderService proxy = (IVoucherOrderService) AopContext.currentProxy();
//            return proxy.createOrder(voucherId);
//        } finally {
//            lock.unlock();
//        }
//    }

    @Transactional
    public void createOrder(VoucherOrder voucherOrder) {
        Long userId = voucherOrder.getUserId();
        int count = Math.toIntExact(query().
                eq("user_id", userId).
                eq("voucher_id", voucherOrder).count());
        log.info("count = {}",count);
        if(count > 0){
           log.error("一人限购一单");
            return ;
        }
        boolean success = seckillVoucherService.update()
                .setSql("stock = stock - 1")
                .eq("voucher_id", voucherOrder.getVoucherId())
                .gt("stock", 0)
                .update();
        if(!success){
            log.error("裤存不足");
            return;
        }
        save(voucherOrder);
    }
}
